EPA spray drift proposal shredded with criticism

Harry Cline | Aug 22, 2002

Not much of a scientific response for a U.S. Environmental Protection Agency administrator, but the comment from San Francisco region administrator Karen Heisler was plenty telling about the agency’s ill-fated attempt to draft new drift control language for pesticides.

Her comment came at the close of a panel she shared with a California Department of Pesticide Regulation chief deputy director Paul Gosselin and University of California, Davis engineer Ken Giles at the 2002 California Plant Health Association regulatory conference recently in Sacramento.

The panel focused on EPA’s first attempt to rewrite pesticide drift control regulations that has been shredded with criticisms like a ream of copy paper tossed into a crop duster’s propeller blades.

A year ago EPA sent out what it calls a PR (Pesticide Registration) notice outlining what it was considering for pesticide drift control regulations on all pesticide registration labels.

EPA might as well have dropped a bomb.

It elicited more than 5,000 letters over a yearlong comment period that was extended twice, a regulatory rarity. As a result Heisler said EPA would start over and rewrite the proposed regulations, and send them out again because the first proposals would, according to the industry:

--Virtually ground aerial applicators year-round due to unrealistic wind speed parameters. Some people have interpreted them to say EPA wants pesticides applied in dead calm wind, although Heisler disputed that. Texas aerial applicators figured they’d be lucky to get airborne 10 days each year under the proposed EPA rules.

--Send aerial applicators who could get airborne on calm days crashing into utility lines because of unsafe height of application requirements.

--Render existing and emerging new spray application technology useless because of mandated large droplet sizes to reduce drift.

--Increase off-target pesticide runoff because of those large droplet sizes.

--Reduce pesticide efficacy and require increased use of pesticides.

EPA’s efforts to bring consistency to application language netted it only a firestorm that also resulted in California Department of Pesticide Regulation putting its re-examination of 30-year old spray drift regulations on hold until EPA figures out what it is going to do.

Heisler said EPA would be issuing a second draft, which will likely be followed by public hearings, perhaps this fall, and another comment period.

Allowed discretion

While it is apparent more consistency must be brought to drift regulations as part of the product registration process, the panelists said it is also clear one size does not fit all for applying pesticides by ground or air. Applicators must be allowed discretion to meet the federal and state laws of "preventing substantial drift off-site."

Reducing drift, said Giles, involves three factors; application equipment, material rates and weather. Rather than an absolute wind speed cutoff of seven to 10 miles per hour, Giles said changing application techniques or lower material rate would allow a pesticide application without substantial drift in high winds.

"The efficacy of many materials drops when droplet sizes increase, and if growers are forced to do apply larger droplets the result could be more frequent applications to gain control or the use of more toxic material," said Giles.

"It is not droplet size that causes drift. It’s the motion of the droplet. You can produce small droplets with much less drip potential than much larger droplets," he said.

Giles said spray technology has made rapid advancement over the past decade with shielded sprayers, electrostatic technology, a wider array of nozzles and weed-seeking and tree and vine sensitive pesticide applicators.

Investments at stake

Many growers and licensed applicators have made considerable investments into new application equipment that would not be in compliance with the EPA’s first spray drift control proposal.

He said spray drift language should not punish people using new technology designed to minimize drift and improve product efficacy.

"You can calculate drift hazard today. The new GPS technology has raised the accountability level for pesticide applications," he said. "At the end of the day you can take the data card out of an applicator that will tell you what has been sprayed where under what weather conditions."

Giles said any spray drift control mandates should be "guidelines to making responsible applications and not limit options" to the grower or applicator.

Gosselin said California has been successfully regulating spray drift for 30 years, and DPR administrators were reluctant to open up the spray drift issue "because it is very complicated and very controversial.

"There is an enormous possibility of doing some stupid things" yet it became apparent as the state agency looked at existing laws that some changes were necessary.

One is reporting "ag to ag" spray drift damage. Many of these are not reported and resolved by insurance companies or producers. "Many of these violations are not fully investigated, and they should be," said Gosselin.

In reviewing DPR regulations, Gosselin said the same product label inconsistencies discovered by EPA also are in California. These need to be clarified, however, he agreed with Giles that any re-writing must not "totally tie the hands of applicators. People must be given some reasonable discretion."